Arsenal left-back Ashley Cole is likely to be out of action for up to a month after undergoing a hernia operation.

Cole had been feeling sore after recent games but the problem worsened during the 0-0 Champions League draw with Ajax last night and the club decided that an operation would be the best course of action.

The England defender had surgery in London earlier today and according to a statement on the club’s website, the operation had been a success.

Cole will miss vital Champions League ties against Roma and Valencia and could also be doubtful for England’s EURO 2004 qualifier against Liechtenstein on 31 March and Turkey on 4 April.

“This was an injury which Ashley had been suffering from this season and it worsened after our UEFA Champions League match against Ajax last night,” the Arsenal statement said.

“Ashley was examined by club medical staff this morning, at which stage it wasdecided to proceed with the operation.”